It’s been a long road for “Road Show.”

The musical from Stephen Sondheim and John Weidman has taken a tortuous path to its Gotham preem, currently in previews and opening Nov. 18 at Off Broadway’s Public Theater.

Since the show’s initial, abortive workshop almost a decade ago, star helmers Sam Mendes and Harold Prince have come and gone, and the tuner has cycled through four different titles.

“Road” finally makes its New York bow under the direction of John Doyle, who brought his theatrically pared-down style to recent revivals of Sondheim’s “Sweeney Todd” and “Company.”

“This is what we were struggling toward,” Weidman says of the latest version. “We’ve really landed on the show we wanted to write.”

Despite setbacks that would have tempted most creatives to drop the project, Sondheim and Weidman kept coming back to it. And since it’s the first new musical from the composer since “Passion” in 1994, the Public run already has legiters wondering about the show’s next stop.

“Road Show” centers on real-life brothers Addison and Wilson Mizner, respectively an architect and a con man, and their journey from Alaska to Florida during the first half of the 20th century.

Sondheim has said he first imagined a show about Wilson — by turns a gold prospector, a realtor and a Broadway producer — in the early 1950s. The idea lay dormant, however, until the mid-1990s, when he and Weidman, his collaborator on “Assassins” and “Pacific Overtures,” began to work in earnest on it, eventually with the support of a $100,000 commission from D.C.’s Kennedy Center.

Called “Wise Guys,” the musical was unveiled in a 1999 development session at New York Theater Workshop. Mendes helmed a cast toplined by Nathan Lane and Victor Garber, and plans for a 2000 Broadway run were announced, with Scott Rudin among the commercial producers attached.

That workshop, however, was largely viewed as a failure, and the Rialto berth was scrapped.

A couple of years later, Prince — reuniting with Sondheim for the first time since “Merrily We Roll Along” in 1981 — signed to helm the newly titled “Gold!” in a production at Chicago’s Goodman Theater.

But in fall 2001, Rudin sued over rights to the show, and the legal tangle delayed the Goodman version for about a year. Prince’s staging of the musical, reworked and retitled “Bounce” and starring Richard Kind and Howard McGillin, opened in 2003, and later that year played the Kennedy Center with an eye toward Broadway.

Critical reception was largely downbeat, including an unencouraging New York Times review from D.C. That incarnation’s commercial producers, including Roger Berlind and Ariel Tepper, decided to nix the New York transfer.

Still, creatives held on. “We’d say, ‘I don’t know if I have the energy to go back,’ ” Weidman says. “But we always got past that.”

Enter Public Theater a.d. Oskar Eustis, who had gotten to know Sondheim during his time at the helm of Trinity Rep in Providence, R.I.

The two continued their relationship when Eustis joined the Public in 2005 and, according to Eustis, the show’s examination of the American idea of success made it a good fit for the politically minded Off Broadway org. “Its subject matter felt exactly right for the Public,” he says.

A reading of “Bounce,” helmed by Eric Schaeffer, was held at the theater in 2006. Eventually Brit director Doyle was brought on for “Bounce” — now called “Road Show.”

The repeated title changes reflect the creatives’ struggle to hone the show’s story and themes. “Ideally the title is connected to what we hope the show is about,” Weidman says.

Eustis adds, “The show had felt like it was an uneasy marriage of different impulses. Now it clearly rides on one.”

Creatives say “Road Show” belongs in the same “boxed set” as the other two Sondheim-Weidman collaborations, which share a historical basis and a gimlet-eyed view of American ideals.

“The show is about what two brothers do with the American Dream, both separately and together, and when opportunity becomes opportunism,” Doyle says.

At the Public, the director has tapped two of his “Sweeney” thesps, Michael Cerveris and Alexander Gemignani, to head a cast of 15 that performs on a spare set also designed by Doyle. The helmer also pushed the writers to cut the intermission, so that the musical now runs about 95 minutes.

“An intermission brings with it all the requirements of traditional musical theater structure,” Doyle says. “But I wanted it to have a fluidity and a sense that everything that happened, happened quickly.”

Creatives are continuing to tinker until opening, when New York critics will take a look at a final product almost 10 years in the making.

As a new piece by a composer-lyricist widely considered to be one of the musical theater’s greatest, commercial producers also will be circling. But none are yet officially attached to the Public incarnation, and until the press weighs in, future life remains a question mark.

For his part, Weidman is unable to look too far into the future. “I think first we’ll go out and have several drinks and a long dinner,” he says.